Movement performance and body size: the relationship for different groups of tests

It has been shown that inconsistently applied normalization for body size could be an important methodological problem in testing physical performance in areas such as sports, physical education, ergonomy, or physical medicine and rehabilitation. The aim of this study was to evaluate a part of the recently proposed classification of physical performance tests (Jaric 2003) based on the role of body size in the tested performance. Presuming a normalization method P(n)= P/ S(b) based on an allometric relationship between the tested performance P and a selected index of body size S (P(n) performance normalized for body size; b allometric parameter), we specifically hypothesized that: (1) the tests of exertion of external force (e.g., lifting weight, pushing, pulling), (2) tests of rapid movements (jumping, sprinting, kicking) and (3) tests of supporting body weight (chin-ups, squats) would reveal the values of the allometric parameters b=0.67, b=0 and b=-0.33 when body size is expressed as body mass, or b=2, b=0 and b=-1 when body size is expressed as body height, respectively. Male physical education students (n=77) were tested on 18 standard physical performance tests belonging to the aforementioned three groups. The obtained values of the allometric parameters proved to be closely in line with the hypothesized ones. While the finding regarding the tests of exertion of external force (i.e., the tested force should be divided by m(0.67) in order to normalize the force for body size) have been already demonstrated by some authors, the findings related to the tests of rapid movements and, particularly, tests of supporting body weight are novel. Although the normalization methods discussed need further evaluation, a more accurate and consistently applied assessment of the body size-independent indices of the evaluated groups of standard tests could improve the methodology of physical performance testing in general.